Photoluminescence Response in Carbon Nanomaterials to Enzymatic Degradation
Photoluminescence Response in Carbon Nanomaterials to Enzymatic Degradation
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DOI：
10.1021/acs.analchem.0c01380
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发表时间：
2020-10-06
影响因子：
7.4
通讯作者：
Star, Alexander
中科院分区：
文献类型：
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作者：
He, Xiaoyun;White, David L.;Star, Alexander
髓过氧化物酶（MPO）是中性粒细胞在炎症过程中释放的一种关键酶，已被证明可以催化碳纳米材料的生物降解。在这项工作中，我们进行MPO催化氧化石墨烯（GO）和表面涂层的原始（6，5）单壁碳纳米管（SWCNTs）的氧化的光致发光研究。酶促降解机制涉及引入缺陷，这促进了进一步降解。有趣的是，GO和SWCNT对酶促降解的光致发光响应相反。虽然SWCNT在998 nm处的近红外（NIR）荧光强度根据表面活性剂身份而不变或降低，但由于石墨烯量子点（GQD）的形成，GO在440 nm处的蓝色荧光强度随着MPO/H2 O2/Cl-的氧化的进展而增加。在嗜中性粒细胞样HL-60细胞中也观察到开启的GO荧光，表明GO在活细胞中成像MPO活性的潜在应用。基于这些结果，我们进一步构建了两个比率传感器，使用SWCNT/GO纳米卷，通过将表面包裹的原始SWCNT作为内部关闭（与胆酸钠（SC））或参考（与羧甲基纤维素（CMC））传感器。比率方法通过提供对从传感器发射的绝对强度不变的响应，使传感器对外部噪声更稳定。我们的传感器显示出对MPO氧化机制的线性响应，并有望用作自校准碳纳米材料基MPO活性指标。
Myeloperoxidase (MPO), a key enzyme released by neutrophils during inflammation, has been shown to catalyze the biodegradation of carbon nanomaterials. In this work, we perform photoluminescence studies on the MPO-catalyzed oxidation of graphene oxide (GO) and surfactant-coated pristine (6,5) singlewalled carbon nanotubes (SWCNTs). The enzymatic degradation mechanism involves the introduction of defects, which promotes further degradation. Interestingly, the photoluminescence responses of GO and SWCNTs to enzymatic degradation are counterposed. Although the near-infrared (NIR) fluorescence intensity of SWCNTs at 998 nm is either unchanged or decreases depending on the surfactant identity, the blue fluorescence intensity of GO at 440 nm increases with the progression of oxidation by MPO/H2O2/Cl- due to the formation of graphene quantum dots (GQDs). Turn-on GO fluorescence is also observed with neutrophil-like HL-60 cells, indicative of potential applications of GO for imaging MPO activity in live cells. Based on these results, we further construct two ratiometric sensors using SWCNT/GO nanoscrolls by incorporating surfactant-wrapped pristine SWCNTs as the internal either turn-off (with sodium cholate (SC)) or reference (with carboxymethylcellulose (CMC)) sensor. The ratiometric approach enables the sensors to be more stable to external noise by providing response invariant to the absolute intensity emitted from the sensors. Our sensors show linear response to MPO oxidative machinery and hold the promise to be used as self-calibrating carbon nanomaterial-based MPO activity indicators.